Mildly interisting result here.
So I'm at a terminal temp of 63 at the 75% setting.
Fans are on high already, I'm surfing a bit, it's been at this temp for a good while.
So I bump up to 85% with the fans STILL on, and after a bit I get a terminal temp lf 67 degrees, not such a rise.
Now I let it cool back down to the low 50's.
Starting fresh with CPU burn it made it to 76 degrees, where it's still at, fluctuating around 75-76.
Perhaps being able to keep the fans on all the time would help.
Did you notice the thread from 5680 users about the fans being on high all the time? I think there all on the ragged edge of cooling ability personaly, and I really, REALLY want to know when the OS is throttling on it's own as mine surly is when it's not disabled. This is a big, big deal to me concerning the P4 in general.
On a side note, any clue what the C2 and C3 cpu settings in the bios are? If they don't ring any bells I'll be more specific when I look again.
Everything seem perfectly fine with your bios, only thing I've not used is the modem as I run a Linux firewall that handles all that, the onboard NIC is fine, as is audio, video. I'll check the modem later for you though. It will likey be this weekend before I get to playing with HT, or I may wait till I decide what to do with this heat stuff.
You've really done some great work here Henrik, and you've been nice enough to not toss it in everyone's face as you could have.
I commend and thank you.